An automatic dosing siphon is a device that allows effluent to be stored in a sewage treatment tank until a pre-determined level is reached. At which time the siphon is activated, the tank is drained to the low water line, the siphon is deactivated, and the tank begins refilling. Automatic dosing siphons contain no moving parts or electrical devices and have been used for on-site sewage treatment to dose a leach field or sand filter.
Although the siphon is extremely simple, and very reliable it is still subject to failure. For example, siphon failures can be caused by heavy inflows into the siphon tank just as the siphon is reaching the end of its cycle. The siphon takes a "gulp" of air which is insufficient to break the siphon and the siphon fails and begins to trickle. Siphon failures are usually one-time events which are normally detected years after the siphon actually failed by a catastrophic failure of the entire sewage treatment system.
Until this invention there has not been an effective method of monitoring siphon performance. Previous methods have included high level water alarms, where a float switch is placed above the high water level, and an alarm is triggered if the water reaches the level of the float switch. This method has proven ineffective because most siphon failures result in water trickling through the siphon before the high water level is reached.
Another method utilizes cycle counters, whereby a digital counter is incremented every time the siphon is activated. If the the counter stops incrementing, a siphon failure is indicated. For this method of monitoring siphon performance, someone must periodically check the counter. Experience has shown that homeowners will not remember to check the counter.
Due to the fact that effective siphon performance monitoring systems did not exist prior to this invention, and because numerous devices exist to monitor pump performance, engineers will often specify that pumps be installed instead of automatic siphons. This invention will eliminate the need for pumps by providing reliable siphon performance monitoring. Additionally, the present invention will provide an automated means of restarting a one-time siphon failure.